新教科版小学六年级科学下册期末重点复习题

<div><div style="text-align: center;"><span style="font-weight: bold;"><font color="#ff0000">新教科版六年级《科学》下册期末重点复习题</font></span></div><div><br></div><br><div style="text-align: center;"><span style="font-weight: bold;"><font color="#38761d">第一单元微小世界</font></span></div><br><span>1、</span><span>人的最高视力只能看清楚(</span><span style=" font-weight:bold; ">1/5毫米</span><span>)大小的微小物体。</span><span>放大镜是(</span><span style=" font-weight:bold; ">凸透镜</span><span>),凸透镜具有(</span><span style=" font-weight:bold; ">放大物体图像</span><span>)的功能,用放大镜观察物体能看到(</span><span style=" font-weight:bold; ">更多的细节</span><span>)</span><span>。&nbsp;&nbsp;</span><br><br><span>2、</span><span>用放大镜观察电视机和计算机的屏幕会看到一个个小点由(</span><span style=" font-weight:bold; ">红</span><span>)、(</span><span style=" font-weight:bold; ">绿</span><span>)、(</span><span style=" font-weight:bold; ">蓝</span><span>)三色组成</span><span>。</span><span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><br><br><span>3、</span><span>人类最早使用的透镜是用(</span><span style=" font-weight:bold; ">透明水晶</span><span>)琢磨而成。英国主教格罗斯泰斯特最早提出(</span><span style=" font-weight:bold; ">放大装置</span><span>)的应用,他的学生(</span><span style=" font-weight:bold; ">培根</span><span>)设计并制造出了能增进视力的眼镜。</span><span>放大镜镜片的特点是(</span><span style=" font-weight:bold; ">透明</span><span>)和(</span><span style=" font-weight:bold; ">中间厚</span><span style=" font-weight:bold; ">边缘薄</span><span>)。只要具有放大镜片透明、中间较厚的结构(比如加满水后的烧杯、烧瓶等),就具有同样的(</span><span style=" font-weight:bold; ">放大</span><span>)功能。</span><span>人们为什么把放大镜又叫凸透镜?因为(</span><span style=" font-weight:bold; ">放大镜中央凸起且又是透明的</span><span>)。</span><br><br><span>4、放大镜的放大倍数和(</span><span style=" font-weight:bold; ">镜片的直径</span><span>)没有关系,和(</span><span style=" font-weight:bold; ">镜片的凸度</span><span>)有关。放大镜的(</span><span style=" font-weight:bold; ">镜片中央凸得越厉害,放大倍数越高</span><span>)</span><span>。</span><br><br><span>5、使用工具能够观察到许多用(</span><span style=" font-weight:bold; ">肉眼</span><span>)观察不到的(</span><span style=" font-weight:bold; ">细节</span><span>)。如通过(</span><span style=" font-weight:bold; ">放大镜</span><span>)能观察到更多关于昆虫的细节:蝇的(</span><span style=" font-weight:bold; ">复眼</span><span>);蟋蟀的耳朵在(</span><span style=" font-weight:bold; ">足的内侧</span><span>);蝴蝶翅膀上布满的彩色小鳞片是(</span><span style=" font-weight:bold; ">扁平的细毛</span><span>)。</span><br><br><span>6、科学研究表明昆虫头上的(</span><span style=" font-weight:bold; ">触角</span><span>)就是它们的(</span><span style=" font-weight:bold; ">“鼻子”</span><span>),能分辨各种气味,比人的鼻子灵敏得多。</span><br><br><span>7、</span><span>组成</span><span>物质</span><span>内部的微粒</span><span>按一定的空间次序排列,形成了(</span><span style=" font-weight:bold; ">有规则的几何外形</span><span>),这就是(</span><span style=" font-weight:bold; ">晶体</span><span>)如食盐、白糖等。</span><br><br><span>8、食盐、白糖的晶体是(</span><span style=" font-weight:bold; ">立方体</span><span>)的,味精的晶体是(</span><span style=" font-weight:bold; ">柱状</span><span>)的。</span><br><br><span>9</span><span>、</span><span>自然界中(</span><span style=" font-weight:bold; ">大部分</span><span>)固体物质都是晶体或由晶体组成,但并不是所有透明的固体都是晶体,如(</span><span style=" font-weight:bold; ">玻璃</span><span>)、(</span><span style=" font-weight:bold; ">松香</span><span>)、(</span><span style=" font-weight:bold; ">琥珀</span><span>)、(</span><span style=" font-weight:bold; ">珍珠</span><span>)等就不是晶体。</span><br><br><span>10、制造晶体的方法:1.(</span><span style=" font-weight:bold; ">减少水分</span><span>);2.(</span><span style=" font-weight:bold; ">降低温度</span><span>)。</span><br><br><span>11、</span><span>两个(</span><span style=" font-weight:bold; ">凸透镜</span><span>)组合起来可以使物体的(</span><span style=" font-weight:bold; ">图像</span><span style=" font-weight:bold; ">放得更大</span><span>)</span><span>。</span><br><br><span>12</span><span>、(</span><span style=" font-weight:bold; ">显微镜</span><span>)</span><span>的发明是人类认识世界的一大飞跃,把人类带入了一个(</span><span style=" font-weight:bold; ">微观世界</span><span>)</span><span>。</span><span>使用显微镜的步骤:①</span><span style=" font-weight:bold; ">安放</span><span>;②</span><span style=" font-weight:bold; ">对光</span><span>;③</span><span style=" font-weight:bold; ">上片</span><span>;④</span><span style=" font-weight:bold; ">调焦</span><span>;⑤</span><span style=" font-weight:bold; ">观察</span><span>。</span><span>显微镜是人类认识(</span><span style=" font-weight:bold; ">微小世界</span><span>)</span><span>的重要观察工具</span><span>,后来人们又研制出了(</span><span style=" font-weight:bold; ">电子</span><span>)显微镜和(</span><span style=" font-weight:bold; ">扫描隧道</span><span>)显微镜,电子显微镜可把物体放大到(</span><span style=" font-weight:bold; ">200万</span><span>)倍</span><span>。</span><br><br><span>1</span><span>3</span><span>、荷兰生物学家(</span><span style=" font-weight:bold; ">列文虎克</span><span>)制成世界上最早的可放大近300倍的</span><span>金属结构的</span><span>(</span><span style=" font-weight:bold; ">显微镜</span><span>),</span><span>发现了(</span><span style=" font-weight:bold; ">微生物</span><span>)。</span><br><br><span>1</span><span>4</span><span>、洋葱表皮</span><span>上一个个小房间似的结构,</span><span>是</span><span>洋葱的</span><span>(</span><span style=" font-weight:bold; ">细胞</span><span>)</span><span>。(</span><span style=" font-weight:bold; ">生物</span><span>)都是由(</span><span style=" font-weight:bold; ">细胞</span><span>)</span><span>组成的。</span><span><br></span><span>1</span><span>5</span><span>、英国科学家(</span><span style=" font-weight:bold; ">罗伯特·胡克</span><span>)</span><span>最早在显微镜下发现了生物的(</span><span style=" font-weight:bold; ">细胞</span><span>)结构</span><span>。</span><br><br><span>1</span><span>6</span><span>、生物细胞的(</span><span style=" font-weight:bold; ">形态</span><span>)是多种多样的,(</span><span style=" font-weight:bold; ">不同生物</span><span>)的细胞是不同的,生物(</span><span style=" font-weight:bold; ">不同器官</span><span>)的细胞也是不同的。</span><br><br><span>1</span><span>7</span><span>、(</span><span style=" font-weight:bold; ">细胞</span><span>)</span><span>是生物最基本的(</span><span style=" font-weight:bold; ">结构单位</span><span>),也是生物最基本的(</span><span style=" font-weight:bold; ">功能单位</span><span>)。</span><br><br><span>1</span><span>8</span><span>、(</span><span style=" font-weight:bold; ">细胞学说</span><span>)的建立被誉为19世纪自然科学的三大发现之一。</span><br><br><span>1</span><span>9</span><span>、用(</span><span style=" font-weight:bold; ">显微镜</span><span>)</span><span>能看到肉眼不能看到的(</span><span style=" font-weight:bold; ">微小生物</span><span>)</span><span>。</span><span>20</span><span>、在水中生活着很多形态各异的(</span><span style=" font-weight:bold; ">微生物</span><span>),如</span><span>草履虫、变形虫</span><span>等。</span><span>利用(</span><span style=" font-weight:bold; ">干草</span><span>)可以培养微小生物。</span><span><br></span><span>21</span><span>、</span><span>洋葱表皮玻片标本的制作步骤:①</span><span style=" font-weight:bold; ">在载玻片上滴一滴水</span><span>;②</span><span style=" font-weight:bold; ">用镊子取下洋葱表皮放到载玻片上展平</span><span>;③</span><span style=" font-weight:bold; ">用盖玻片倾斜盖到标本上</span><span>;④</span><span style=" font-weight:bold; ">从从标本边缘滴一滴碘酒给标本染色</span><span>。</span><br><br><span>22、微生物装片的制作步骤:①</span><span style=" font-weight:bold; ">先取少量脱脂棉交织成网状放在载玻片上</span><span>;②</span><span style=" font-weight:bold; ">在棉纤维上滴一滴池塘水,盖上盖玻片</span><span>。放棉纤维的目的是为了(</span><span style=" font-weight:bold; ">控制微生物的活动</span><span>)。</span><span><br></span><span>23</span><span>、微生物通常都有特殊的(</span><span style=" font-weight:bold; ">构造和功能</span><span>)</span><span>,以适应周围的环境。(</span><span style=" font-weight:bold; ">微生物</span><span>)具有(</span><span style=" font-weight:bold; ">生物</span><span>)</span><span>的特征,如:对环境有一定的需求、对外界的刺激有反应、能繁殖等。</span><span>常见的微生物有(</span><span style=" font-weight:bold; ">草履虫、变形虫、喇叭虫、眼虫和团藻</span><span>)等。</span><br><br><span>2</span><span>4</span><span>、人类(</span><span style=" font-weight:bold; ">观察工具</span><span>)的改进,使人类观察的范围扩大,发现了仅靠肉眼无法发现的自然界的许多秘密:肉眼(</span><span style=" font-weight:bold; ">能看清昆虫等较小的动物</span><span>)——放大镜(</span><span style=" font-weight:bold; ">放大几倍到几十倍,</span><span style=" font-weight:bold; ">能看清小于毫米的肉眼看不清的东西</span><span>)——光学显微镜(</span><span style=" font-weight:bold; ">放大到1500倍,</span><span style=" font-weight:bold; ">能看清细胞和微生物</span><span>)——电子显微镜(</span><span style=" font-weight:bold; ">放大到200万倍,</span><span style=" font-weight:bold; ">能看到更小的</span><span style=" font-weight:bold; ">细菌、病毒和</span><span style=" font-weight:bold; ">组成物质的原子、分子</span><span>)——</span><span>扫描隧道显微镜(</span><span style=" font-weight:bold; ">放大到3亿倍,能直接操纵原子或分子</span><span>)</span><span>。</span><span><br></span><span>21、人类探索(</span><span style=" font-weight:bold; ">微小世界</span><span>)的成果,促进了科学技术的发展、社会的进步和人类生活的改善。如:(1)利用显微镜发现细菌、病毒,抵抗制服疾病(2)克隆生物(3)利用微生物酿酒、发面、制作酱油、醋、酸奶等(4)利用微生物处理垃圾和污水。</span><span><br></span><br></div>{$setpage}<div><br><br><div style="text-align: center;"><span style="font-weight: bold;"><font color="#38761d">第二单元物质的变化</font></span></div><br><span>1、</span><span>我们能直接或间接观察到的(</span><span style=" font-weight:bold; ">实际存在</span><span>)的东西都是物质。</span><span>世界是</span><span>由</span><span>(</span><span style=" font-weight:bold; ">物质</span><span>)</span><span>构成的</span><span>。</span><br><br><span>2、物质是(</span><span style=" font-weight:bold; ">变化</span><span>)的</span><span>,</span><span>一些物质的变化(</span><span style=" font-weight:bold; ">产生了新的物质</span><span>),另一些变化(</span><span style=" font-weight:bold; ">没有产生新的物质</span><span>)。</span><br><br><span>3、在变化中(</span><span style=" font-weight:bold; ">不能产生新物质</span><span>)的我们称为(</span><span style=" font-weight:bold; ">物理变化</span><span>)</span><span>,能(</span><span style=" font-weight:bold; ">产生新的物质</span><span>)的变化我们称为(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>。</span><br><br><span>4、比如豆子和沙子的实验,在混合和分离的前后没有变化,没有变为或产生新的物质,我们称为(</span><span style=" font-weight:bold; ">物理变化</span><span>)</span><span>。像白糖加热从白色的糖变为黑色的炭一样(</span><span style=" font-weight:bold; ">产生了新的物质</span><span>)的变化,我们就称</span><span>为(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>。</span><br><br><span>5、物质的变化可以划分为(</span><span style=" font-weight:bold; ">物理变化</span><span>)</span><span>和(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>,它们的区别在于(</span><span style=" font-weight:bold; ">是不是</span><span style=" font-weight:bold; ">产生了新的物质</span><span>)</span><span>。</span><br><br><span>6、一些物质在变化的过程中,会既发生(</span><span style=" font-weight:bold; ">化学变化</span><span>)又发生(</span><span style=" font-weight:bold; ">物理变化</span><span>),如蜡烛燃烧、白糖加热时融化变色。</span><br><br><span>7、</span><span>分别说出加热白糖实验中的物理和化学变化:(</span><span style=" font-weight:bold; ">开始固体的白糖在加热后变成液体状的糖属于物理变化;继续加热,白糖的颜色逐渐变深直到变成黑炭状,气味由无味到闻到焦味,这些现象属于化学变化</span><span>)。</span><br><br><span>8、(</span><span style=" font-weight:bold; ">米饭</span><span>)在口腔里与(</span><span style=" font-weight:bold; ">唾液</span><span>)作用会发生(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>,产生一种糖类所以咀嚼米饭会有甜味</span><span>。(</span><span style=" font-weight:bold; ">淀粉</span><span>)与(</span><span style=" font-weight:bold; ">碘酒</span><span>)会发生化学变化,生成的新物质是(</span><span style=" font-weight:bold; ">蓝紫色</span><span>)的</span><span>,利用这一特性可以检验食物中是否含有(</span><span style=" font-weight:bold; ">淀粉</span><span>)</span><span>。</span><br><br><span>9、(</span><span style=" font-weight:bold; ">小苏打</span><span>)和(</span><span style=" font-weight:bold; ">白醋</span><span>)混合后会发生化学反应,产生新的物质(</span><span style=" font-weight:bold; ">二氧化碳气体</span><span>)</span><span>,这样的变化属</span><span>于(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>。</span><br><br><span>10、(</span><span style=" font-weight:bold; ">二氧化碳</span><span>)是具有特殊性质的一种气体</span><span>,它具有(</span><span style=" font-weight:bold; ">比空气重</span><span>)、(</span><span style=" font-weight:bold; ">不支持燃烧</span><span>)的性质</span><span>。</span><br><br><span>11、铁生锈是一种(</span><span style=" font-weight:bold; ">化学变化</span><span>)</span><span>,(</span><span style=" font-weight:bold; ">铁锈</span><span>)是一种不同于(</span><span style=" font-weight:bold; ">铁</span><span>)的新物质。</span><span>铁和铁锈在(</span><span style=" font-weight:bold; ">颜色</span><span>)、(</span><span style=" font-weight:bold; ">硬度</span><span>)、(</span><span style=" font-weight:bold; ">导电性</span><span>)、(</span><span style=" font-weight:bold; ">是否能被磁铁吸引</span><span>)等方面都不同(</span><span style=" font-weight:bold; ">铁灰白色、硬度高、导电性好、能被磁铁吸引;铁锈红褐色、硬度低、基本不导电、不被磁铁吸引</span><span>)。</span><br><br><span>12、铁生锈的原因</span><span>与(</span><span style=" font-weight:bold; ">水和空气</span><span>)有关</span><span>,即(</span><span style=" font-weight:bold; ">水和空气</span><span>)的共同作用使铁生锈。</span><span>铁生锈的快慢与(</span><span style=" font-weight:bold; ">水的多少</span><span>)</span><span>关系很大。</span><span>把铁与(</span><span style=" font-weight:bold; ">水、空气</span><span>)隔绝开</span><span>是防止(</span><span style=" font-weight:bold; ">铁生锈</span><span>)的好方法,如</span><span style=" font-weight:bold; ">刷油漆、电镀</span><span>等。</span><br><br><span>13、(</span><span style=" font-weight:bold; ">硫酸铜溶液</span><span>)和(</span><span style=" font-weight:bold; ">铁钉</span><span>)会发生(</span><span style=" font-weight:bold; ">化学反应</span><span>)</span><span>,产生(</span><span style=" font-weight:bold; ">新的物质</span><span>)</span><span>。反应现象:浸入溶液的铁钉表面有(</span><span style=" font-weight:bold; ">红色</span><span>)物质附着,浅蓝色的硫酸铜溶液会逐渐变(</span><span style=" font-weight:bold; ">浅</span><span>)。</span><br><br><span>14、</span><span>(</span><span style=" font-weight:bold; ">化学变化</span><span>)会伴随各种现象,如:(</span><span style=" font-weight:bold; ">改变颜色</span><span>)、(</span><span style=" font-weight:bold; ">发光发热</span><span>)、(</span><span style=" font-weight:bold; ">产生沉淀物</span><span>)、(</span><span style=" font-weight:bold; ">产生气体</span><span>)</span><span>,根据这些现象可以初步判断物质是否发生了化学变化。</span><br><br><span>15、物质的变化与人类的生产生活有着紧密的联系,人类进行的所有的生产活动和人类的生活,都是利用了(</span><span style=" font-weight:bold; ">物质的变化</span><span>)。1</span><span>6</span><span>、</span><span>中国古代的黑火药是(</span><span style=" font-weight:bold; ">硝石</span><span>)、(</span><span style=" font-weight:bold; ">硫黄</span><span>)、(</span><span style=" font-weight:bold; ">木炭</span><span>)以及一些辅料等粉末状物质的均匀混合物。</span><br><br></div>{$setpage}<div><br><br><div style="text-align: center;"><span style="font-weight: bold;"><font color="#38761d">第三单元宇宙</font></span></div><br><span>1、(</span><span style=" font-weight:bold; ">月球</span><span>)是地球的(</span><span style=" font-weight:bold; ">卫星</span><span>),在运动方式、体积大小、引力大小、表面特征等诸多方面同地球不同。</span><br><br><span>2、月球围绕地球(</span><span style=" font-weight:bold; ">逆时针</span><span>)方向运行。月球</span><span>直径约是地球的(</span><span style=" font-weight:bold; ">1/4</span><span>);质量约是地球的(</span><span style=" font-weight:bold; ">1/80</span><span>);体积约是地球的(</span><span style=" font-weight:bold; ">1/49</span><span>);</span><span>引力大约是地球的(</span><span style=" font-weight:bold; ">1/6</span><span>)。</span><br><br><span>3、1969年7月,(</span><span style=" font-weight:bold; ">美国</span><span>)的(</span><span style=" font-weight:bold; ">阿波罗11号</span><span>)载人飞船成功地在月球上着陆,(</span><span style=" font-weight:bold; ">阿姆斯特朗</span><span>)留下人类在月球上的第一个足迹。</span><br><br><span>4、月球在(</span><span style=" font-weight:bold; ">圆缺变化</span><span>)过程中出现的各种(</span><span style=" font-weight:bold; ">形状</span><span>)叫做(</span><span style=" font-weight:bold; ">月相</span><span>)</span><span>,</span><span>月相在(</span><span style=" font-weight:bold; ">一个月</span><span>)的不同时期有不同的(</span><span style=" font-weight:bold; ">形状</span><span>)。</span><br><br><span>5、月相变化是(</span><span style=" font-weight:bold; ">月球</span><span>)围绕(</span><span style=" font-weight:bold; ">地球</span><span>)公转过程中形成的,变化是有一定规律的。</span><span>月相变化依次为(</span><span style=" font-weight:bold; ">新月</span><span>)→(</span><span style=" font-weight:bold; ">蛾眉月</span><span>)→(</span><span style=" font-weight:bold; ">上弦月</span><span>)→(</span><span style=" font-weight:bold; ">凸月</span><span>)→(</span><span style=" font-weight:bold; ">满月</span><span>)→(</span><span style=" font-weight:bold; ">凸月</span><span>)→(</span><span style=" font-weight:bold; ">下弦月</span><span>)→(</span><span style=" font-weight:bold; ">蛾眉月</span><span>)→(</span><span style=" font-weight:bold; ">新月</span><span>)。</span><br><br><span>6、农历上半月由</span><span>(</span><span style=" font-weight:bold; ">缺</span><span>)</span><span>到</span><span>(</span><span style=" font-weight:bold; ">圆</span><span>)</span><span>,下半月再由</span><span>(</span><span style=" font-weight:bold; ">圆</span><span>)</span><span>到</span><span>(</span><span style=" font-weight:bold; ">缺</span><span>)</span><span>。</span><span>画月相防错口诀:</span><span>上半月</span><span style=" font-weight:bold; ">右亮逐渐充满</span><span>;</span><span>下半月</span><span style=" font-weight:bold; ">左亮逐渐消减</span><span>。</span><br><br><span>7、月球是一个(</span><span style=" font-weight:bold; ">不发光</span><span>)、(</span><span style=" font-weight:bold; ">不透明</span><span>)的(</span><span style=" font-weight:bold; ">球体</span><span>),我们看到的月光是它(</span><span style=" font-weight:bold; ">反射</span><span>)太阳的光。月相实际上就是人们从地球上看到的(</span><span style=" font-weight:bold; ">月球被太阳照亮的部分</span><span>)。由于观察的角度不同,所以看到的月相(</span><span style=" font-weight:bold; ">亮面大小</span><span>)、(</span><span style=" font-weight:bold; ">方向</span><span>)也就不同。</span><br><br><span>8、(</span><span style=" font-weight:bold; ">环形山</span><span>)是月球地形的主要特征。</span><span>环行山的特点:(</span><span style=" font-weight:bold; ">数量众多;杂乱分布;有大有小;有深有浅</span><span>)。</span><br><br><span>9、环形山的形成与许多因素有关,(</span><span style=" font-weight:bold; ">陨石撞击</span><span>)是主要原因。</span><br><br><span>10、有关环形山形成原因,目前公认的观点是(“</span><span style=" font-weight:bold; ">撞击说</span><span>”),这种观点认为环形山是长期以来(</span><span style=" font-weight:bold; ">流星</span><span>)、(</span><span style=" font-weight:bold; ">陨石</span><span>)撞击后留下的痕迹,因为月球上没有(</span><span style=" font-weight:bold; ">空气</span><span>),就相当于少了一层保护层,使撞击更猛烈和频繁。</span><span>还有一种观点是(“</span><span style=" font-weight:bold; ">火山爆发说</span><span>”)。</span><br><br><span>11、(</span><span style=" font-weight:bold; ">日食</span><span>)和(</span><span style=" font-weight:bold; ">月食</span><span>)是日、地、月三个天体运动形成的天文现象。</span><br><br><span>12、(</span><span style=" font-weight:bold; ">月球</span><span>)运行到(</span><span style=" font-weight:bold; ">太阳</span><span>)和(</span><span style=" font-weight:bold; ">地球</span><span>)中间,地球处于月影中时,因(</span><span style=" font-weight:bold; ">月球</span><span>)挡住了太阳照射到地球上的光形成(</span><span style=" font-weight:bold; ">日食</span><span>)。而(</span><span style=" font-weight:bold; ">月食</span><span>)则是月球运行到地球的影子中,(</span><span style=" font-weight:bold; ">地球</span><span>)挡住了太阳射向月球的光。</span><br><br><span>13、月球运行到(</span><span style=" font-weight:bold; ">太阳和地球</span><span>)中间,三者在一条直线上,因月球挡住了太阳照射到地球上的光形成日食。而月食则是月球运行到地球的影子中,地球居于(</span><span style=" font-weight:bold; ">太阳和月球</span><span>)之间,三者在一条直线上,地球挡住了太阳射向月球的光就发生了月食。</span><br><br><span>14、(</span><span style=" font-weight:bold; ">太阳</span><span>)和围绕它运动的(</span><span style=" font-weight:bold; ">行星</span><span>)、(</span><span style=" font-weight:bold; ">矮行星</span><span>)和(</span><span style=" font-weight:bold; ">小天体</span><span>)组成了(</span><span style=" font-weight:bold; ">太阳系</span><span>)。太阳系是一个较大的(</span><span style=" font-weight:bold; ">天体系统</span><span>)。</span><br><br><span>15、以(</span><span style=" font-weight:bold; ">太阳</span><span>)为中心,包括围绕它转动的(</span><span style=" font-weight:bold; ">八大行星</span><span>)及其卫星、(</span><span style=" font-weight:bold; ">矮行星</span><span>)、(</span><span style=" font-weight:bold; ">小天体</span><span>)(包括小行星、流星、彗星等)组成的天体系统叫做(</span><span style=" font-weight:bold; ">太阳系</span><span>)。</span><br><br><span>16、太阳系里有八大行星:(</span><span style=" font-weight:bold; ">水星、金星、地球、火星、木星、土星、天王星、海王星</span><span>)。</span><br><br><span>17、人们为了便于辨认星星,把看起来不动的星星分成群,划分成不同的(</span><span style=" font-weight:bold; ">区域</span><span>),根据其形态想象成(</span><span style=" font-weight:bold; ">人</span><span>)、(</span><span style=" font-weight:bold; ">动物</span><span>)或(</span><span style=" font-weight:bold; ">其他物体</span><span>)的形状,并给它们命名,这些人为划分的</span><span>天空中的</span><span>区域就称为(</span><span style=" font-weight:bold; ">星座</span><span>)。</span><br><br><span>18、(</span><span style=" font-weight:bold; ">星座</span><span>)是远近不同、没有联系的(</span><span style=" font-weight:bold; ">恒星</span><span>)在天空中的(</span><span style=" font-weight:bold; ">视觉图像</span><span>)。如果从不同角度观察,图形不同。</span><br><br><span>19、(</span><span style=" font-weight:bold; ">大熊星座</span><span>)的明显标志就是我们熟悉的、由七颗亮星组成的(</span><span style=" font-weight:bold; ">北斗七星</span><span>)</span><span>;小熊星座的主要标志是(</span><span style=" font-weight:bold; ">北极星</span><span>)</span><span>。</span><br><br><span>20、(</span><span style=" font-weight:bold; ">北极星</span><span>)可以帮助大家在夜间辨认方向,利用(</span><span style=" font-weight:bold; ">大熊星座的北斗七星</span><span>)可以比较容易地找到它:把北斗七星勺子前沿的两颗星的连线延长,在大约相当于这两颗星距离的5倍处,有一颗比较亮的星,那就是(</span><span style=" font-weight:bold; ">北极星</span><span>)。</span><br><br><span>21、随季节的变换,在天空中会出现不同的代表性星座。星座在天空中是</span><span>(</span><span style=" font-weight:bold; ">运动变化</span><span>)</span><span>的。</span><br><br><span>22、(</span><span style=" font-weight:bold; ">亮星构成的图形</span><span>)是星座的主要标志。(</span><span style=" font-weight:bold; ">北斗七星</span><span>)是大熊星座的主要标志。</span><br><br><span>23、夏季天空中有许多亮星,其中的三颗亮星(</span><span style=" font-weight:bold; ">天津四</span><span>)(属于</span><span style=" font-weight:bold; ">天鹅座</span><span>)、(</span><span style=" font-weight:bold; ">织女星</span><span>)(属于</span><span style=" font-weight:bold; ">天琴座</span><span>)和(</span><span style=" font-weight:bold; ">牛郎星</span><span>)(属于</span><span style=" font-weight:bold; ">天鹰座</span><span>)构成了一个巨大的三角形,人们称之为(“</span><span style=" font-weight:bold; ">夏季大三角</span><span>”)。</span><span>南部天空有一颗红巨星心宿二,它属于(</span><span style=" font-weight:bold; ">天蝎</span><span>)座。</span><br><br><span>24、宇宙空间分布着大小不同的(</span><span style=" font-weight:bold; ">天体系统</span><span>)。(</span><span style=" font-weight:bold; ">宇宙</span><span>)是由类似太阳系、银河系、河外星系等大小不同的天体系统组成的庞大的系统,它在不断</span><span>地</span><span>运动变化。</span><br><br><span>25、宇宙是(</span><span style=" font-weight:bold; ">运动变化</span><span>)的,(</span><span style=" font-weight:bold; ">膨胀</span><span>)的,组成宇宙的(</span><span style=" font-weight:bold; ">天体</span><span>)也是运动变化着的。</span><br><br><span>26、</span><span>宇宙中每时每刻都有许多恒星诞生,同时也有许多恒星消亡。恒星都在不停地(</span><span style=" font-weight:bold; ">高速运动</span><span>)。</span><br><br><span>27、太阳系和众多的恒星一起组成的一个(</span><span style=" font-weight:bold; ">恒星集团</span><span>),被人们称为(</span><span style=" font-weight:bold; ">银河系</span><span>)。</span><br><br><span>28、银河系大约由(</span><span style=" font-weight:bold; ">1000亿——2000亿</span><span>)颗恒星组成,直径有(</span><span style=" font-weight:bold; ">10万光年</span><span>)。</span><br><br><span>29、光的传播速度是(</span><span style=" font-weight:bold; ">每秒钟30万千米</span><span>),(</span><span style=" font-weight:bold; ">光年</span><span>)就是光在(</span><span style=" font-weight:bold; ">一年</span><span>)中所走的距离,它是用来计量恒星间(</span><span style=" font-weight:bold; ">距离</span><span>)的单位。</span><br><br><span>30、银河系还不是宇宙的全部,类似银河系一样的星系还有100亿个,人们把它们统称为(</span><span style=" font-weight:bold; ">河外星系</span><span>)。</span><br><br><span>31、我国是世界上公认的(</span><span style=" font-weight:bold; ">火箭</span><span>)发源地。早在距今1700多年前的(</span><span style=" font-weight:bold; ">三国时代</span><span>)的古籍上就出现了(“</span><span style=" font-weight:bold; ">火箭</span><span>”)的名称。</span><br><br></div>{$setpage}<div><br><br><div style="text-align: center;"><span style="font-weight: bold;"><font color="#38761d">第四单元环境和我们</font></span></div><br><span>1、人们在生活中要产生大量成分复杂的(</span><span style=" font-weight:bold; ">垃圾</span><span>)。丢弃的垃圾</span><span>会</span><span>(</span><span style=" font-weight:bold; ">危害环境</span><span>)。</span><span>垃圾分类方法:</span><span style=" font-weight:bold; ">按材料分</span><span>可分为</span><span style=" font-weight:bold; ">塑料、金属、纸、玻璃</span><span>等;</span><span style=" font-weight:bold; ">按原来的用途分</span><span>可分为</span><span style=" font-weight:bold; ">食物、包装、用品、衣物、电器</span><span>等;</span><span style=" font-weight:bold; ">按危害状况分</span><span>可分为</span><span style=" font-weight:bold; ">有害垃圾和一般垃圾</span><span>。</span><br><br><span>2、目前处理垃圾的方法有(</span><span style=" font-weight:bold; ">填埋</span><span>)、(</span><span style=" font-weight:bold; ">焚烧</span><span>)</span><span>和(</span><span style=" font-weight:bold; ">堆肥</span><span>)</span><span>等,但填埋、焚烧的方法还是会影响环境。</span><br><br><span>3、垃圾填埋场对周围环境的危害有:(1)</span><span style=" font-weight:bold; ">散发恶臭,污染空气</span><span style=" font-weight:bold; ">、水源</span><span>(2)</span><span style=" font-weight:bold; ">滋生蚊蝇,引发疾病</span><span>(3)</span><span style=" font-weight:bold; ">造成土壤污染,影响农业生产</span><span>。</span><br><br><span>4、焚烧垃圾的优点:(1)</span><span style=" font-weight:bold; ">占地小,使垃圾减量</span><span>(2)</span><span style=" font-weight:bold; ">避免污染地下水</span><span>(3)</span><span style=" font-weight:bold; ">产生的热量可用来发电</span><span>;缺点</span><span>:</span><span style=" font-weight:bold; ">对周围空气产生严重污染</span><span>。</span><br><br><span>5、(</span><span style=" font-weight:bold; ">设计合理</span><span>)的(</span><span style=" font-weight:bold; ">垃圾填埋场</span><span>)能有效减少对环境的污染。</span><br><br><span>6、(</span><span style=" font-weight:bold; ">减少垃圾</span><span>)很重要,常用的方法是(</span><span style=" font-weight:bold; ">减少丢弃</span><span>)和(</span><span style=" font-weight:bold; ">重新使用</span><span>)。</span><br><br><span>7、日常生活中以下垃圾是可以减少的:(1)</span><span style=" font-weight:bold; ">双面打印可以节约纸张</span><span>(2)</span><span style=" font-weight:bold; ">自带喝水杯外出,少买瓶装饮料</span><span>(3)</span><span style=" font-weight:bold; ">尽量少用或不用一次性用品,以减少纸和塑料的丢弃</span><span>……</span><br><br><span>8、(</span><span style=" font-weight:bold; ">过度包装</span><span>)会造成(</span><span style=" font-weight:bold; ">资源浪费</span><span>)而且产生大量垃圾。</span><br><br><span>9、垃圾中的一些原材料可以重新(</span><span style=" font-weight:bold; ">回收利用</span><span>),包括纸、金属、塑料、玻璃等。这样可以(</span><span style=" font-weight:bold; ">减少垃圾、节约资源</span><span>)。</span><br><br><span>10、</span><span>生活垃圾一般分四类:厨余垃圾、可回收垃圾、有害垃圾和一般垃圾。</span><span>要有效地回收垃圾,必须改变(</span><span style=" font-weight:bold; ">垃圾混装</span><span>)的习惯,对生活垃圾进行(</span><span style=" font-weight:bold; ">分类</span><span>)和(</span><span style=" font-weight:bold; ">分装</span><span>)。</span><br><br><span>11、垃圾分类、分装便于垃圾(</span><span style=" font-weight:bold; ">回收利用</span><span>)和对一些(</span><span style=" font-weight:bold; ">有毒垃圾</span><span>)的处理。</span><br><br><span>12、对自然环境威胁最大的五种物质,电池里就包含了三种:(</span><span style=" font-weight:bold; ">汞</span><span>)、(</span><span style=" font-weight:bold; ">铅</span><span>)、(</span><span style=" font-weight:bold; ">镉</span><span>)。</span><span>一节一号电池能使(</span><span style=" font-weight:bold; ">1平方米</span><span>)土壤失去利用价值,一粒纽扣电池可使(</span><span style=" font-weight:bold; ">600吨</span><span>)水无法饮用。</span><br><br><span>13、(</span><span style=" font-weight:bold; ">堆肥法</span><span>)可以有效减少垃圾并形成(</span><span style=" font-weight:bold; ">肥料</span><span>)。</span><br><br><span>14、减少固体垃圾的科学方法是(</span><span style=" font-weight:bold; ">减少丢弃</span><span>)、(</span><span style=" font-weight:bold; ">重新使用</span><span>)和(</span><span style=" font-weight:bold; ">回收利用</span><span>)。</span><br><br><span>15、人们生活中要用掉大量的水,(</span><span style=" font-weight:bold; ">淡水资源</span><span>)很紧缺。</span><br><br><span>16、由于(</span><span style=" font-weight:bold; ">人口迅速增长</span><span>)、(</span><span style=" font-weight:bold; ">环境污染</span><span>)和(</span><span style=" font-weight:bold; ">全球气候变暖</span><span>),目前60%的大陆面临淡水资源不足,100多个国家严重缺水,其中最严重的国家达(</span><span style=" font-weight:bold; ">40多个</span><span>)。</span><br><br><span>17、在淡水资源短缺的情况下,水污染更给人类和其他生物造成了威胁。水污染主要是(</span><span style=" font-weight:bold; ">人类的活动</span><span>)造成的。</span><br><br><span>18、水的污染源可能来自(</span><span style=" font-weight:bold; ">农业的杀虫剂、肥料</span><span>)等,可能来自(</span><span style=" font-weight:bold; ">工业的废水、油污</span><span>)等,可能来自(</span><span style=" font-weight:bold; ">家庭的洗涤剂、人的排泄物</span><span>),也可能来自(</span><span style=" font-weight:bold; ">动物的尸体</span><span>)等。</span><br><br><span>19、淡水在自来水厂中除了(</span><span style=" font-weight:bold; ">沉淀</span><span>)和(</span><span style=" font-weight:bold; ">过滤</span><span>)之外,还要加入药物进行(</span><span style=" font-weight:bold; ">灭菌处理</span><span>)才符合我们使用的标准。</span><br><br><span>20、污水需经过(</span><span style=" font-weight:bold; ">复杂的处理</span><span>)才能使用,一般要通过三种方法(</span><span style=" font-weight:bold; ">物理方法、生物方法、化学方法</span><span>)获得净化。物理方法主要就是分离水中的杂物和较大的颗粒,杂物有塑料袋、菜叶杂草等;生物方法是通过细菌分解水中的污物;化学方法主要是用于消毒,通常的做法是向水中加人化学药剂——</span><span>(</span><span style=" font-weight:bold; ">氯</span><span>)</span><span>,通过它来有效杀灭水中的病源微生物。</span><br><br><span>21、当前突出的环境问题有(</span><span style=" font-weight:bold; ">垃圾</span><span>)、(</span><span style=" font-weight:bold; ">水污染</span><span>)、(</span><span style=" font-weight:bold; ">大气污染</span><span>)、(</span><span style=" font-weight:bold; ">白色污染</span><span>)、(</span><span style=" font-weight:bold; ">物种灭绝速度加快</span><span>)等,人类正着力于相应的环境保护行动。</span><br><br><span>22、(</span><span style=" font-weight:bold; ">减少废气和废物排放</span><span>)是控制大气污染最根本的办法。近年来,我国积极推广(“</span><span style=" font-weight:bold; ">无车日</span><span>”)活动,以节约能源和保护环境。</span><br><br><span>23、减少白色污染(塑料垃圾)的方法有:(1)</span><span style=" font-weight:bold; ">用纸袋和布袋</span><span>(2)</span><span style=" font-weight:bold; ">提菜篮子上菜市</span><span>(3)</span><span style=" font-weight:bold; ">减少塑料包装</span><span>(4)</span><span style=" font-weight:bold; ">用可降解塑料袋</span><span>。</span><br><br><span>24、由于(</span><span style=" font-weight:bold; ">全球森林的大量破坏</span><span>)和(</span><span style=" font-weight:bold; ">海洋环境的恶化</span><span>),现有的生物物种灭绝速度是自然灭绝速度的(</span><span style=" font-weight:bold; ">1000倍</span><span>)。人类(</span><span style=" font-weight:bold; ">滥捕乱猎</span><span>)和(</span><span style=" font-weight:bold; ">过度开发利用</span><span>),更使得许多生物资源濒临枯竭。</span><br><br><span>25、建立</span><span>(</span><span style=" font-weight:bold; ">自然保护区</span><span>)</span><span>是保护生物多样性的有效方法,我国的(</span><span style=" font-weight:bold; ">九寨沟</span><span>)、(</span><span style=" font-weight:bold; ">长白山</span><span>)、(</span><span style=" font-weight:bold; ">四川卧龙</span><span>)等地都建立了自然保护区。</span><br><br><span>26、许多环境问题是(</span><span style=" font-weight:bold; ">人类活动</span><span>)造成的,但人类的活动也能够</span><span>(</span><span style=" font-weight:bold; ">改善环境</span><span>)</span><span>。</span><br></div>